Large-scale Lithium-ion Batteries Research Articles

Up-to-date development of lithium-ion batteries in Japan

In this paper, the authors review the up-to-date development of lithium-ion batteries (LIBs), focusing mainly on the situation in Japan. The materials, constructions, and electrochemical performance of the latest commercially available LIBs, including lithium polymer batteries, which have come onto the market only fairly recently, are described in the first half of this article. The authors then discuss the recent trends in the development of battery materials for LIBs as well as those of large-scale LIBs.

Development of 1 kW h class lithium ion battery for power storage

With the aim of developing 1 kW h class lithium ion batteries with long life and high efficiencies, we trial manufactured batteries that were fabricated using LiCoO 2 and natural graphite as cathode and anode materials, respectively, with 1 M LiPF 6 diluted by EC/DEC as an electrolyte. Fundamental studies necessary for the development of a large-scale battery consisting of laminated large electrodes were conducted, examining various factors. These factors were selected from the observations of batteries dismantled after the battery life reached an end point. The construction of the batteries was based on the results of fundamental research done to elucidate the problems encountered in the present study. We achieved 543 cycles with high efficiencies with the fourth battery. It is noteworthy that technical factors such as homogeneous impregnation of the electrolyte into the electrode laminates and maintenance of uniform conditions of laminates by the control of expansion and contraction accompanied with charge and discharge, respectively, were very important for the long life of large-scale lithium ion batteries.

Design and characteristics of large-scale lithium ion battery

Adequate cell design, especially concerning energy density and cycle life, is important for the development of large-scale lithium ion batteries. In this study, we were able to survey the expansion and shrinkage of the layer-built electrodes of a prismatic cell during charge and discharge tests. Natural graphite and mesophase carbon micro beads (MCMB) were used as anode active material for the comparison purpose. Based on the findings of this study, a plate spring and lightweight battery case were designed. In addition, an improved large-scale battery employing these parts was manufactured for further examination.